Internet service provider (ISP) Internet backbone routers, in particular provider-edge (PE) routers, make use of packet-processing engines that are based on expensive custom silicon, e.g., application specific integrated circuits (ASICs), to achieve both high packet-processing rates and to store a large forwarding table or forwarding information block (FIB) to hold a full set of Internet and customer routes. For example the forwarding table may store 750,000 to more than 1,000,000 entries.